Obesity is considered a major health problem with annual associated costs reaching $100 billion in the U.S. alone. Morbid obesity is a condition of obesity with the presence of a secondary debilitating progressive disease and is generally associated with a body mass index (BMI) ≧40 kg/m2. While the basic mechanism of obesity is simply an imbalance between caloric intake and burn rate, the underlying factors are varied and complex and conservative attempts at sustained weight loss with this population are almost always unsuccessful. Often, there are genetic and other biological influences that may override environmental causes. Consequently, obesity is a disease that eludes a simple treatment, with a recurrence rate above 90% for those who attempt to lose weight. Moreover, long-term results using conservative treatments for morbid obesity are generally unsuccessful and are typically associated with further loss of self-esteem with the regaining of weight. Hypertension, cardiovascular disease, diabetes, along with a host of other comorbidities all make morbid obesity second only to smoking as a preventable cause of death.
Surgical procedures for obesity date back to 1889 (Billroth) with the earliest peer reviewed procedure being the jejuno-ileal bypass in 1954 (Kreman). A successful procedure is commonly defined as one that results in at least 50% excess weight loss at 2 years. Today, the most commonly done operation is the Roux-en-Y gastric bypass (RYGB), with around 35,000 performed annually in the U.S. Other forms of bariatric surgery include Fobi pouch, bilio-pancreatic diversion, and gastroplasty or “stomach stapling”. The single existing procedure that involves an implanted device is the Lap-Band, which is a laparoscopically installed inflatable cuff that is placed around the top of the stomach just below the lower esophageal sphincter (LES). This device affects satiety only (no reduced caloric absorption). Because there is more to obesity than simple overeating, it is unlikely that Lap-Band by itself will ever be as effective as a surgery that includes other physiologic feedback mechanisms.
The RYGB procedure is a procedure which has become very common in bariatric surgery. This procedure facilitates the movement of the jejunum to a high position by using a retrocolic Roux-en-Y loop. The procedure is generally performed through a 6-8 inch incision extending from the end of the breastbone to just above the navel. The stomach is completely divided into 2 unequal portions (a smaller upper and a larger lower gastric pouch) using an automatic stapling device with the raw surface reinforced with additional sutures. The upper pouch typically measures less than about 1 ounce or 20 cc, while the lower larger pouch remains generally intact and continues to secrete stomach juices flowing through the intestinal tract.
A segment of the small intestine (just distal of the duodenum or proximal of the jejunum) is then brought from the lower abdomen and joined with the upper pouch to form an end-to-end anastomosis created through a half-inch opening, also called the stoma. This segment of the small intestine is called the “Roux loop” and carries food from the upper pouch to the remainder of the intestines, where the food is digested. The remaining lower pouch and the attached segment of duodenum are then reconnected to form another anastomotic connection to the Roux loop at a location approximately 50-150 cm (1.6-4.9 ft) from the stoma, typically using a stapling instrument. It is at this connection that the digestive juices from the bypassed stomach, pancreas, and liver enter the jejunum or ileum to aid in the digesting of food. Due to the small size of the upper pouch, patients are forced to eat at a slower rate and are satiated much more quickly, thereby reducing the caloric intake (typically between about 1000-1200 Calories).
Because the food enters the intestines directly, conditions known as the “dumping syndrome” are created when certain types of “junk foods” are consumed (usually sweets and other simple carbohydrates). This creates unpleasant feelings of nausea, diarrhea, nervousness, and sweating, which in turn discourages patients from developing unhealthy eating patterns. With the RYGB procedure, a loss of at least 50% of excess body weight (EBW) is maintained in approximately 60% of patients at 5 years with a reduced complication rate than other procedures.
In creating the anastomoses in the RYGB procedure, several methods have previously been developed to maintain channel integrity. However, the conventional RYGB procedure requires a great deal of operative time and because of the degree of invasiveness, post-operative recovery time can be quite lengthy and painful.
Aside from the RYGB procedure, another gastrointestinal disease which relates to the stomach is gastroesophageal reflux disease (GERD). The lower esophageal sphincter is located in a distal portion of the esophagus adjacent to the junction between the esophagus and the stomach. When food is digested, a properly functioning lower esophageal sphincter would allow food to pass from the esophagus to the stomach while preventing reverse flow. However, GERD is a disorder where the esophageal sphincter allows the stomach contents, which includes gastric acid and bile, to flow back into the distal portion of the esophagus. Some complications associated with GERD include heartburn, pulmonary disorders, chest pain, esophageal ulcers, esophagitis, Barrett's esophagus, and esophageal carcinoma.
Common treatments for GERD include the administration of prescription acid blockers. But these drugs afford only short term relief; additionally, these drugs can be expensive and may have long-term side effects. Surgical procedures have included a procedure called the Nissen fundoplication, where a portion of the gastric fundus is wrapped around the esophagus. The wrapped fundus applies pressure to the esophagus to limit the reverse flow of the stomach contents. Effectively elongating the esophagus by fundoplication or by extending it via a staple line may be done to treat GERD. Conventional fundoplication procedures may be effective at treating GERD, but they also have disadvantages. For instance, many of these procedures require large incisions to be made in a patient. Laparoscopic procedures typically require several smaller incisions formed in the abdominal wall for the insertion of instruments into the patient's body. However, such procedures can be expensive and they can increase the risks of post-operative hernias, accidental organ perforations, and other related drawbacks.
Examples related to the field of gastroplasty are described below.
U.S. Pat. No. 5,549,621 to Bessler et al., which is incorporated herein by reference in its entirety, pertains to an apparatus and method for performing vertical banded gastroplasty without the use of staples. The described device uses at least two clamping bars to create a tubular-shaped pouch. However, the device is deployed laparoscopically onto the external surface of the stomach.
U.S. Pat. No. 5,382,231 to Shlain, which is incorporated herein by reference in its entirety, describes a device for transesophageal stomach retraction by a device having vacuum ports utilized to draw the stomach over the device. However, this device is used for manipulating and retracting a patient's stomach from the inside during a variety of surgical procedures and is not a permanent procedure for creating an internal pouch within the stomach itself.
U.S. Pat. No. 5,345,949 to Shlain, which is incorporated herein by reference in its entirety, relates to laparoscopic methods and tools for inserting a banding device to bring the walls of the stomach adjacent to one another between the proximal pouch and the distal region of the stomach. But there is no procedure for the creation of an internal pouch internally created from the stomach.
Examples related to the field of GERD treatment are described below.
U.S. Pat. No. 6,159,146 to El Gazayerli, which is incorporated herein by reference in its entirety, relates to a device which is inserted transesophageally and engages the inside anterior wall of the fundus and secures it to the side of the esophagus.
U.S. Pat. No. 6,113,609 to Adams, which is incorporated herein by reference in its entirety, pertains to a system which includes placement of a distal anchor through a hole formed in the wall of the esophagus and through a hole formed in the gastric wall, which are then fastened together.
U.S. Pat. No. 5,571,116 to Bolanos et al., which is incorporated herein by reference in its entirety, pertains to an invagination device which approximates the lower esophagus and the fundus of the stomach.
However, all of these examples are limited to treatments for GERD which involves the attachment of the fundus, or upper portion of the stomach, to the esophagus.